1. Field of the Invention
The present invention relates to improvements in tracer cartridges or projectiles for visually aiding the aiming and firing of guns.
2. Description of the Prior Art
The terms"projectile" or "bullet" are used herein to designate the complete round, including cartridge case, propellant and primer. Armor piercing projectiles usually consist of a hardened steel core, gilding metal jacket and lead filler to fill the space between the point of the core and the point of the jacket.
Tracer-type projectiles have long been known in the prior art. Such projectiles facilitate the accurate aiming and firing of guns. This is because the flight path of the projectile can be followed with the eye and correction made as required to hit the target. Tracing is particularly useful as a visual aid in combat and military training, especially at night.
Projectiles with the tracing feature, in the prior art, have been of the base burning or base fuming type, similar to a nozzleless and throatless end burning solid propellant rocket motor. Tracer compositions, a chemical agent that emits light, that is, visible radiation, or smoke, are usually arranged to be ignited by hot propellant gases and do not utilize an igniter of any kind.
Base-burning tracer-type projectiles have a number of disadvantages, one of which is their visibility from the base only. Others include limitations on (a) their velocity for a given bullet mass and form coefficient, and (b) permissible bullet core hardness, because of bore friction. There thus exists a need and a demand in the art for an improvement in tracer-type projectiles.